Analog Devices Inc. DC996B-A

Overview

LTC2208 from Analog Devices (acquired Linear Technology) is a 16-bit, 130Msps analog-to-digital converter optimized for high-frequency, wide-dynamic-range signal digitization up to 700MHz full-power bandwidth. It features a programmable gain amplifier (PGA), 70fs RMS aperture jitter, 78dBFS noise floor, and ±4LSB INL - deployed in cellular base station receivers and spectrum analyzers requiring undersampling capability.

For engineers reviewing the LTC2208 datasheet, LTC2208 pinout, LTC2208 application, or LTC2208 equivalent, this page delivers verified specifications, validated LVDS/CMOS output configurations, PGA input range selection (1.5VP-P or 2.25VP-P), clock duty cycle stabilization, and real-world performance data at 250MHz input with >83dB SFDR.

Technical Context

The LTC2208 employs a 16-bit pipelined ADC core with integrated sample-and-hold and PGA front end, supporting differential analog inputs up to 700MHz. Its ultra-low 70fsRMS jitter enables high-fidelity undersampling of RF signals without external clock cleanup.

Digital outputs are configurable as standard or low-power LVDS (100Ω terminated) or single-ended CMOS (0.5V–3.6V swing), with optional demultiplexing to halve data rate. Clock encoding accepts differential (LVDS/PECL) or single-ended (TTL/CMOS) inputs, and an on-chip duty cycle stabilizer maintains performance across 25%–75% clock duty cycles.

Key Specifications

Pinout & Package

64-lead (9mm × 9mm) plastic QFN package with exposed ground pad (Pin 65). Requires soldering of exposed pad to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed ADC applications.

Compared with AD9653BCPZ-125 and LTC2207IUP, the LTC2208 uniquely combines 130Msps speed, 700MHz bandwidth, and on-chip PGA - making it the only option among the three capable of direct undersampling of LTE-A carrier aggregations above 200MHz without external gain or filtering.

Availability

LTC2208 is available at Aetrix Electronics and suitable for cellular infrastructure, test instrumentation, and medical imaging systems requiring stable component supply, long-term obsolescence planning, and traceable sourcing.

Supply support for LTC2208 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving communications, industrial, automotive, and healthcare markets.

The LTC2208 belongs to ADI's high-speed precision ADC product line, engineered for demanding RF and instrumentation applications where wide bandwidth, low jitter, and flexible digital interfacing are essential.

FAQ

What is the maximum analog input frequency supported by the LTC2208?

The LTC2208 supports a full-power analog input bandwidth of 700MHz, enabling direct sampling of RF signals in the UHF and low microwave bands. This specification is measured with RS < 25Ω source impedance and applies across the full operating temperature range for both C-grade (0°C to 70°C) and I-grade (–40°C to 85°C) versions of the LTC2208.

Does the LTC2208 support both LVDS and CMOS digital outputs?

Yes, the LTC2208 supports multiple output formats via the LVDS pin (Pin 61): Standard LVDS, Low-Power LVDS, full-rate CMOS, and demultiplexed CMOS. The CMOS outputs allow swing adjustment from 0.5V to 3.6V using OVDD, while LVDS modes require 100Ω differential termination at the receiver.

How does the PGA pin affect the LTC2208's input range and performance?

The PGA pin (Pin 64) selects between two input ranges: low = 2.25VP-P (1× gain), high = 1.5VP-P (1.5× gain). Both configurations maintain the same 16-bit resolution and DC accuracy, but the PGA setting optimizes SNR for different signal amplitudes - critical when digitizing low-level RF signals or high-level IF outputs.

What is the purpose of the SENSE pin on the LTC2208?

The SENSE pin (Pin 1) configures the reference architecture: tied to VDD selects the internal 2.5V bandgap reference; connected to external 1.25V or 2.5V sources enables ratiometric or calibrated measurement systems. Both reference options yield a full-scale ADC range of 2.25VP-P when PGA = 0.

Can the LTC2208 operate with non-50% clock duty cycles?

Yes - the LTC2208 includes an optional clock duty cycle stabilizer enabled via the MODE pin (Pin 62). When activated, it corrects duty cycles from 25% to 75%, maintaining timing margins and AC performance without requiring external clock conditioning circuitry.